Inflammatory abdominal aortic aneurysms constitute approximately 15% of all abdominal aortic aneurysms. Macroscopically, they are characterised by a thick white rind of fibrous tissue, which may extend to the retroperitoneum to encase and obstruct adjacent hollow organs. This may require major changes and modifications in exposure and operative technique. Currently, diagnostic accuracy is poor in inflammatory aortic aneurysm disease, and little is known of its pathogenesis. This leads to many such aneurysms remaining unsuspected pre-operatively, and contributes to the increased operative morbidity and mortality of this disease. A review of the history of vascular surgery and radiology is undertaken, with a particular emphasis on aneurysm disease. Current theories of the aetiology of both simple and inflammatory aneurysm are discussed. An account is given of the current state of radiological techniques in the diagnosis of inflammatory aneurysm disease, and a brief technical synopsis of magnetic resonance imaging (MRI) is provided. A retrospective series was studied, comprising 47 patients with IA and 162 patients with SA of matched age and sex distribution. No differences were found in the incidence of diabetes, smoking, symptomatic occlusive vascular disease or hypertension. Pain was slightly more common in the IA group, but weight loss was not. Plasma viscosity was the only measured haematological parameter which differed significantly between the groups, being higher in the IA group compared to the other two. Biochemical evidence of renal failure was a poor predictor of ureteric involvement in fibrosis. Post-operative ultrasound failed to make the diagnosis of IA in all cases subsequently confirmed at operation. Computerised tomography (CT) made the diagnosis in only 13 of 25 cases. All aortic replacements were carried out using the transperitoneal route. In 4 cases of IA however, unexpectedly extensive abdominal inflammatory change required the abdominal incision to be extended as a left eighth rib thoracotomy. 63% of patients with IA required bifurcation grafts rather than tube grafts, the figures being almost exactly reversed for patients with SA.